Patchwork PCI/hotplug/rphahp: Fix endianess issues

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Submitter Laurent Dufour
Date April 10, 2014, 1:02 p.m.
Message ID <20140410130213.8435.16459.stgit@nimbus>
Download mbox | patch
Permalink /patch/338113/
State Accepted
Headers show

Comments

Laurent Dufour - April 10, 2014, 1:02 p.m.
Numerical values stored in the device tree are encoded in Big Endian and
should be byte swapped when running in Little Endian.

RPA hot plug module should convert those values as well.

Note that in rpaphp_get_drc_props the comparison between indexes[i+1] and
*index is done using the BE values (whatever is the current endianess).
This doesn't matter since we are checking for equality here. This way only
the returned value is byte swapped.

RPA also made RTAS calls which implies BE values to be used. According to
the patch done in RTAS (http://patchwork.ozlabs.org/patch/336865), no
additional conversion is required in RPA.

Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
---
 drivers/pci/hotplug/rpaphp_core.c |   15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)


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Bjorn Helgaas - April 25, 2014, 5:50 p.m.
On Thu, Apr 10, 2014 at 03:02:13PM +0200, Laurent Dufour wrote:
> Numerical values stored in the device tree are encoded in Big Endian and
> should be byte swapped when running in Little Endian.
> 
> RPA hot plug module should convert those values as well.
> 
> Note that in rpaphp_get_drc_props the comparison between indexes[i+1] and
> *index is done using the BE values (whatever is the current endianess).
> This doesn't matter since we are checking for equality here. This way only
> the returned value is byte swapped.
> 
> RPA also made RTAS calls which implies BE values to be used. According to
> the patch done in RTAS (http://patchwork.ozlabs.org/patch/336865), no
> additional conversion is required in RPA.
> 
> Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>

I applied this to pci/hotplug for v3.16, thanks!

> ---
>  drivers/pci/hotplug/rpaphp_core.c |   15 +++++++++------
>  1 file changed, 9 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/pci/hotplug/rpaphp_core.c b/drivers/pci/hotplug/rpaphp_core.c
> index 4796c15..984d708 100644
> --- a/drivers/pci/hotplug/rpaphp_core.c
> +++ b/drivers/pci/hotplug/rpaphp_core.c
> @@ -223,16 +223,16 @@ int rpaphp_get_drc_props(struct device_node *dn, int *drc_index,
>  	type_tmp = (char *) &types[1];
>  
>  	/* Iterate through parent properties, looking for my-drc-index */
> -	for (i = 0; i < indexes[0]; i++) {
> +	for (i = 0; i < be32_to_cpu(indexes[0]); i++) {
>  		if ((unsigned int) indexes[i + 1] == *my_index) {
>  			if (drc_name)
>  				*drc_name = name_tmp;
>  			if (drc_type)
>  				*drc_type = type_tmp;
>  			if (drc_index)
> -				*drc_index = *my_index;
> +				*drc_index = be32_to_cpu(*my_index);
>  			if (drc_power_domain)
> -				*drc_power_domain = domains[i+1];
> +				*drc_power_domain = be32_to_cpu(domains[i+1]);
>  			return 0;
>  		}
>  		name_tmp += (strlen(name_tmp) + 1);
> @@ -321,16 +321,19 @@ int rpaphp_add_slot(struct device_node *dn)
>  	/* register PCI devices */
>  	name = (char *) &names[1];
>  	type = (char *) &types[1];
> -	for (i = 0; i < indexes[0]; i++) {
> +	for (i = 0; i < be32_to_cpu(indexes[0]); i++) {
> +		int index;
>  
> -		slot = alloc_slot_struct(dn, indexes[i + 1], name, power_domains[i + 1]);
> +		index = be32_to_cpu(indexes[i + 1]);
> +		slot = alloc_slot_struct(dn, index, name,
> +					 be32_to_cpu(power_domains[i + 1]));
>  		if (!slot)
>  			return -ENOMEM;
>  
>  		slot->type = simple_strtoul(type, NULL, 10);
>  
>  		dbg("Found drc-index:0x%x drc-name:%s drc-type:%s\n",
> -				indexes[i + 1], name, type);
> +				index, name, type);
>  
>  		retval = rpaphp_enable_slot(slot);
>  		if (!retval)
> 
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Patch

diff --git a/drivers/pci/hotplug/rpaphp_core.c b/drivers/pci/hotplug/rpaphp_core.c
index 4796c15..984d708 100644
--- a/drivers/pci/hotplug/rpaphp_core.c
+++ b/drivers/pci/hotplug/rpaphp_core.c
@@ -223,16 +223,16 @@  int rpaphp_get_drc_props(struct device_node *dn, int *drc_index,
 	type_tmp = (char *) &types[1];
 
 	/* Iterate through parent properties, looking for my-drc-index */
-	for (i = 0; i < indexes[0]; i++) {
+	for (i = 0; i < be32_to_cpu(indexes[0]); i++) {
 		if ((unsigned int) indexes[i + 1] == *my_index) {
 			if (drc_name)
 				*drc_name = name_tmp;
 			if (drc_type)
 				*drc_type = type_tmp;
 			if (drc_index)
-				*drc_index = *my_index;
+				*drc_index = be32_to_cpu(*my_index);
 			if (drc_power_domain)
-				*drc_power_domain = domains[i+1];
+				*drc_power_domain = be32_to_cpu(domains[i+1]);
 			return 0;
 		}
 		name_tmp += (strlen(name_tmp) + 1);
@@ -321,16 +321,19 @@  int rpaphp_add_slot(struct device_node *dn)
 	/* register PCI devices */
 	name = (char *) &names[1];
 	type = (char *) &types[1];
-	for (i = 0; i < indexes[0]; i++) {
+	for (i = 0; i < be32_to_cpu(indexes[0]); i++) {
+		int index;
 
-		slot = alloc_slot_struct(dn, indexes[i + 1], name, power_domains[i + 1]);
+		index = be32_to_cpu(indexes[i + 1]);
+		slot = alloc_slot_struct(dn, index, name,
+					 be32_to_cpu(power_domains[i + 1]));
 		if (!slot)
 			return -ENOMEM;
 
 		slot->type = simple_strtoul(type, NULL, 10);
 
 		dbg("Found drc-index:0x%x drc-name:%s drc-type:%s\n",
-				indexes[i + 1], name, type);
+				index, name, type);
 
 		retval = rpaphp_enable_slot(slot);
 		if (!retval)